U.S. Patent Application Publication No. 20120260740 describes a strap having one or more built-in sensors. The strap may be used, for example, in trucking, for securing loads inside a trailer or on the bed of a trailer. The sensors may wirelessly transmit tension data to a portable electronic device, such as a smart phone. This allows a user to monitor the tension on one or more straps without having to physically examine them. U.S. Pat. No. 7,972,099 describes a self-tensioning tie down assembly and safety system for tightening the retaining straps securing cargo on a carrier. Retaining straps are connected to winches connected to the carrier. A ratchet system is used to tighten the winch. A two bar torque linkage has a ratchet arm connectable to the ratchet wheel of the winch via a socket and has a connector arm connected to an actuator. The actuator is connected to a pneumatic/electrical circuit and provides reciprocating linear motion thereby actuating the torque linkage. The torque linkage may be set in a tightening or loosening position. The required tension level of the retaining strap is pre-set. Pressure within the circuit drives the actuator thereby actuating the torque linkage which tightens the strap on the winch until the tension level is reached. Signals are sent to a display panel to indicate when a strap is loose.
U.S. Pat. No. 8,432,290 describes a force measuring ratchet tie down system in the field of goods holding; more particularly the '290 device is said to address technical problems such as insufficiently tight binding, severe difficulty in control and trouble in adjustment. The force measuring ratchet tie down includes a body assembly, a handle, a teeth stop board, a catch and scroll. The handle is connected with the body assembly through the scroll. A binding belt having a fixable outer end is connected to the body assembly. Another binding belt having a fixable outer end is rolled on the scroll. A ratchet is fixed on the scroll. The body assembly is movably connected with a teeth stop board the end of which could be embedded among the teeth of the ratchet. The handle is movably connected with a catch the end of which could be embedded among the teeth of the ratchet. A sensor is placed at a forced part of the tie down, which is linked with a signal processing circuit and could generate a signal corresponding to the size of the tensioning force of the binding belt when the tie down is in operation. A display device is connected to the signal processing circuit. The force measuring ratchet tie down of the '290 Patent has alleged advantages that include a high safety property, a compact structure, and a low manufacturing cost.
Foreign Patent Application Publication Number EP1467193 describes a system for monitoring the position of a belt around an object, and comprises a belt unit with a force sensor for measuring the tension of a belt around an object, a transmitter for cable or wireless transmission of a tension measurement signal, and a power supply. A display unit is also included, and has a receiver for the tension measurement signal and a display device for optical and/or acoustic display of the tension information.
U.S. Pat. No. 7,112,023 describes a tension alert device that is attached between opposing ends of a securing member attached to a load bed to secure a load thereupon. The device has a strip with a curved portion, which is resiliently movable towards a proximity sensor disposed on a wall in device. When tension in securing member decreases, proximity of the curved portion relative wall decreases. When the curved portion enters a proximity actuation state relative to a first wall corresponding to a low tension state, then the tension is determined to be below a tension threshold level, and a proximity sensor actuates a signaling device that alerts a user.
U.S. Pat. No. 8,506,220 describes a sensing device that during normal operation is attached to a tensioned strap holding a load on a vehicle. A probe engages the strap and causes a signal lamp to light up if the tension in the strap is below a predetermined threshold value. The sensing device helps the vehicle operator to set the tension correctly before a journey and also provides a visible warning if a strap becomes loose during the journey. The warning is visible beyond the vehicle, to alert other road users to a possible hazard.